Bioconjugation is a descriptive term for the joining of two or more different molecular species by chemical or biological means, in which at least one of the molecular species is a biological macromolecule. This includes conjugation of proteins, peptides, polysaccharides, lectins, hormones, nucleic acids, liposomes and cells, with each other or with any other molecular species that add useful properties, including radionuclides, toxins, haptens, inhibitors, fluorophores, ligands, etc. Immobilization of biological macromolecules is also considered a special case of bioconjugation in which the macromolecule is conjugated, either reversibly or irreversibly, to an insoluble support. Bioconjugation is utilized extensively in biochemical, immunochemical and molecular biological research. Applications of bioconjugation are numerous, and include affinity chromatography, affinity cytochemistry, histochemistry, pathological probe detection, diagnostics, signal amplification, immunoassay, hybridoma technology, blotting technology, bioaffinity sensors, gene probe detection, cross-linking reagents, affinity targeting, affinity perturbation, drug delivery, fusogenic reagents, immobilizing reagents, selective retrieval, selective elimination, flow cytometry and cytological probe detection.